package com.lhl.security.jwt.filter;

import com.lhl.security.jwt.util.TestJwtUtils;
import io.swagger.annotations.Api;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.authentication.www.BasicAuthenticationFilter;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

/**
 * @className: com.lhl.security.jwt.filter.JWTAuthorizationFilter
 * @description: T验证成功当然就是进行鉴权了
 * 登录成功之后走此类进行鉴权操作
 * @author: king
 * @date: 2020-11-09
 **/
@Api(tags = "JWTAuthorizationFilter", produces = "")
public class JWTAuthorizationFilter extends BasicAuthenticationFilter {
    public JWTAuthorizationFilter(AuthenticationManager authenticationManager) {
        super(authenticationManager);
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request,
                                    HttpServletResponse response,
                                    FilterChain chain) throws IOException, ServletException {

        String tokenHeader = request.getHeader(TestJwtUtils.TOKEN_HEADER);
        // 如果请求头中没有Authorization信息则直接放行了
        if (tokenHeader == null || !tokenHeader.startsWith(TestJwtUtils.TOKEN_PREFIX)) {
            chain.doFilter(request, response);
            return;
        }
        // 如果请求头中有token，则进行解析，并且设置认证信息
        SecurityContextHolder.getContext().setAuthentication(getAuthentication(tokenHeader));
        super.doFilterInternal(request, response, chain);
    }

    // 这里从token中获取用户信息并新建一个token
    private UsernamePasswordAuthenticationToken getAuthentication(String tokenHeader) {
        String token = tokenHeader.replace(TestJwtUtils.TOKEN_PREFIX, "");
        String username = TestJwtUtils.getUsername(token);
        List<String> roles = TestJwtUtils.getUserRole(token);
        if (username != null){
            /*return new UsernamePasswordAuthenticationToken(username, null,
                    Collections.singleton(new SimpleGrantedAuthority(role))
            );*/
            List<SimpleGrantedAuthority> ls = new ArrayList<>();
            for (String role : roles) {
                ls.add(new SimpleGrantedAuthority(role));
            }
            Collection<? extends GrantedAuthority> authorities = new ArrayList<SimpleGrantedAuthority>(ls);
            return new UsernamePasswordAuthenticationToken(username, null,authorities);
        }
        return null;
    }
}
